Bone loss in chronic liver diseases:Could healthy liver be a requirement for good bone health?

Given that the liver is involved in many metabolic mechanisms,it is not surprising that chronic liver disease(CLD)could have numerous complications.Secondary osteoporosis and increased bone fragility are frequently overlooked complications in CLD patients.Previous studies implied that up to one-third of these individuals meet diagnostic criteria for osteopenia or osteoporosis.Recent publications indicated that CLD-induced bone fragility depends on the etiology,duration,and stage of liver disease.Therefore,the increased fracture risk in CLD patients puts a severe socioeconomic burden on the health system and urgently requires more effective prevention,diagnosis,and treatment measures.The pathogenesis of CLD-induced bone loss is multifactorial and still insufficiently understood,especially considering the relative impact of increased bone resorption and reduced bone formation in these individuals.It is essential to note that inconsistent findings regarding bone mineral density measurement were previously reported in these individuals.Bone mineral density is widely used as the“golden standard”in the clinical assessment of bone fragility although it is not adequate to predict individual fracture risk.Therefore,microscale bone alterations(bone microstructure,mechanical properties,and cellular indices)were analyzed in CLD individuals.These studies further support the thesis that bone strength could be compromised in CLD individuals,implying that an individualized approach to fracture risk assessment and subsequent therapy is necessary for CLD patients.However,more well-designed studies are required to solve the bone fragility puzzle in CLD patients.

Collagen matrix scaffolds:Future perspectives for the management of chronic liver diseases

Approximately 1.5 billion chronic liver disease(CLD)cases have been estimated worldwide,encompassing a wide range of liver damage severities.Moreover,liver disease causes approximately 1.75 million deaths per year.CLD is typically characterized by the silent and progressive deterioration of liver parenchyma due to an incessant inflammatory process,cell death,over deposition of extracellular matrix proteins,and dysregulated regeneration.Overall,these processes impair the correct function of this vital organ.Cirrhosis and liver cancer are the main complications of CLD,which accounts for 3.5%of all deaths worldwide.Liver transplantation is the optimal therapeutic option for advanced liver damage.The liver is one of the most common organs transplanted;however,only 10%of liver transplants are successful.In this context,regenerative medicine has made significant progress in the design of biomaterials,such as collagen matrix scaffolds,to address the limitations of organ transplantation(e.g.,low donation rates and biocompatibility).Thus,it remains crucial to continue with experimental and clinical studies to validate the use of collagen matrix scaffolds in liver disease.

Antioxidant and anti-inflammatory agents in chronic liver diseases:Molecular mechanisms and therapy

Chronic liver disease(CLD)is a continuous process that causes a reduction of liver function lasting more than six months.CLD includes alcoholic liver disease(ALD),non-alcoholic fatty liver disease(NAFLD),chronic viral infection,and autoimmune hepatitis,which can lead to liver fibrosis,cirrhosis,and cancer.Liver inflammation and oxidative stress are commonly associated with the development and progression of CLD.Molecular signaling pathways such as AMPactivated protein kinase(AMPK),C-Jun N-terminal kinase,and peroxisome proliferator-activated receptors(PPARs)are implicated in the pathogenesis of CLD.Therefore,antioxidant and anti-inflammatory agents from natural products are new potent therapies for ALD,NAFLD,and hepatocellular carcinoma(HCC).In this review,we summarize some powerful products that can be potential applied in all the stages of CLD,from ALD/NAFLD to HCC.The selected agents such asβ-sitosterol,curcumin,genistein,and silymarin can regulate the activation of several important molecules,including AMPK,Farnesoid X receptor,nuclear factor erythroid 2-related factor-2,PPARs,phosphatidylinositol-3-kinase,and lysyl oxidase-like proteins.In addition,clinical trials are undergoing to evaluate their efficacy and safety.

Hypoxia,angiogenesis and liver fibrogenesis in the progression of chronic liver diseases

Angiogenesis is a dynamic,hypoxia-stimulated and growth factor-dependent process,and is currently referred to as the formation of new vessels from preexisting blood vessels.Experimental and clinical studies have unequivocally reported that hepatic angiogenesis,irrespective of aetiology,occurs in conditions of chronic liver diseases(CLDs) characterized by perpetuation of cell injury and death,inflammatory response and progressive fibrogenesis.Angiogenesis and related changes in liver vascular architecture,that in turn concur to increase vascular resistance and portal hypertension and to decrease parenchymal perfusion,have been proposed to favour fibrogenic progression of the disease towards the end-point of cirrhosis.Moreover,hepatic angiogenesis has also been proposed to modulate the genesis of portal-systemic shunts and increase splanchnic blood flow,thus potentially affecting complications of cirrhosis.Hepatic angiogenesis is also crucial for the growth and progression of hepatocellular carcinoma.Recent literature has identified a number of cellular and molecular mechanisms governing the cross-talk between angiogenesis and fibrogenesis,with a specifi c emphasis on the crucial role of hypoxic conditions and hepatic stellate cells,particularly when activated to the myofibroblast-like pro-fibrogenic.Experimental anti-angiogenic therapy has been proven to be effective in limiting the progression of CLDs in animal models.From a clinical point of view,anti-angiogenic therapy is currently emerging as a new pharmacologic intervention in patients with advanced fibrosis and cirrhosis.

New insight of vitamin D in chronic liver diseases

BACKGROUND： Vitamin D is a fat-soluble sterol derivative that is predominantly synthesized in the liver and has multiple functions. The accumulative data showed that the clinical manifestations and prognosis of chronic liver diseases are associated with serum vitamin D levels. DATA SOURCES： A PubMed and Google Scholar search using terms： ＂vitamin D＂, ＂25 （OH）D＂, ＂liver disease＂, ＂viral hepatitis＂, ＂non-alcoholic fatty liver disease＂, ＂liver fibrosis＂, ＂cirrhosis＂, ＂hepatocellular carcinoma＂ and ＂autoimmune liver disease＂ was performed, and relevant articles published in English between January 2000 and March 2014 were reviewed. Fulb text publications relevant to the field were selected and relevant articles from reference lists were also included. RESULTS： The insufficiency or deficiency of vitamin D is common in various kinds of chronic liver diseases including viral hepatitis B and C. Serum 25-hydroxyvitamin D and vitamin D receptors are possibly interrelated with the incidence, treatment and prognosis of diseases. Though the evidence of vitamin D supplementation in viral hepatitis and associated liver diseases is still limited, there is great potential to apply this adjuvant therapy to improve the treatments. CONCLUSIONS： Although the exact role and mechanisms of vitamin D have not been fully elucidated in chronic liver diseases, it is potentially beneficial in the treatment of chronic liver diseases. Further mechanistic studies are needed to validate its clinical application.

Critical role of estrogen in the progression of chronic liver diseases

Background:Estrogens regulate sexual function and also have a significant role in various pathophysiological processes.Estrogens have a non-reproductive role as the modulators of the immune system,growth,neuronal function,and metabolism.Estrogen receptors are expressed in the liver and their impaired expression and function are implicated with obesity and liver associated metabolic dysfunctions.The purpose of the current review is to discuss the disparity role of estrogens on several forms of liver diseases.Data sources:A comprehensive search in PubMed and EMBASE was conducted using the keywords“estrogens and liver diseases”,“estradiol and liver diseases”,“hormones and liver diseases”,“endocrine function in liver diseases”,and“female hormones in liver diseases”.Relevant papers published before September 30,2019 were included.Results:The present review confirms the imperative role of estrogen in various forms of chronic liver diseases.Estrogens play a key role in maintaining homeostasis and make the liver less susceptible to several forms of chronic liver diseases in healthy premenopausal individuals.In contrast,clinical studies also showed increased estrogen levels with chronic liver diseases.Conclusions:Several studies reported the protective role of estrogens in chronic liver diseases and this has been widely accepted and confirmed in experimental studies using ovariectomized rat models.However,in a few clinical studies,increased estrogen levels are also implicated in chronic liver diseases.Therefore,further studies are warranted at molecular level to explore the role of estrogen in various forms of chronic liver diseases.

Helicobacter Infection and Chronic Liver Diseases

This paper reviews the recent Helicobacter infection associated with chronic liver disease. The bacteriology, prevalence, pathogenesis and diagnosis were reviewed. Future work should be conducted on the pathogenesis and treatment of this disease.

Inflammation and fibrosis in chronic liver diseases including nonalcoholic fatty liver disease and hepatitis C

At present chronic liver disease(CLD),the third commonest cause of premature death in the United Kingdom is detected late,when interventions are ineffective,resulting in considerable morbidity and mortality.Injury to the liver,the largest solid organ in the body,leads to a cascade of inflammatory events.Chronic inflammation leads to the activation of hepatic stellate cells that undergo transdifferentiation to become myofibroblasts,the main extra-cellular matrix producing cells in the liver;over time increased extra-cellular matrix production results in the formation of liver fibrosis.Although fibrogenesis may be viewed as having evolved as a“wound healing”process that preserves tissue integrity,sustained chronic fibrosis can become pathogenic culminating in CLD,cirrhosis and its associated complications.As the reference standard for detecting liver fibrosis,liver biopsy,is invasive and has an associated morbidity,the diagnostic assessment of CLD by non-invasive testing is attractive.Accordingly,in this review the mechanisms by which liver inflammation and fibrosis develop in chronic liver diseases are explored to identify appropriate and meaningful diagnostic targets for clinical practice.Due to differing disease prevalence and treatment efficacy,disease specific diagnostic targets are required to optimally manage individual CLDs such as non-alcoholic fatty liver disease and chronic hepatitis C infection.To facilitate this,a review of the pathogenesis of both conditions is also conducted.Finally,the evidence for hepatic fibrosis regression and the mechanisms by which this occurs are discussed,including the current use of antifibrotic therapy.

Liver tumors in children with chronic liver diseases

Liver tumors are rare in children,but the incidence may increase in some circumstances and particularly in chronic liver diseases.Most liver tumors consequent to chronic liver diseases are malignant hepatocellular carcinoma.Other liver tumors include hepatoblastoma,focal nodular hyperplasia,adenoma,pseudotumor,and nodular regenerative hyperplasia.Screening of suspected cases is beneficial.Imaging and surrogate markers of alpha-fetoprotein are used initially as noninvasive tools for surveillance.However,liver biopsy for histopathology evaluation might be necessary for patients with inconclusive findings.Once the malignant liver tumor is detected in children with cirrhosis,liver transplantation is currently considered the preferred option and achieves favorable outcomes.Based on the current evidence,this review focuses on liver tumors with underlying chronic liver disease,their epidemiology,pathogenesis,early recognition,and effective management.

Gastrointestinal and hepatic side effects of potential treatment for COVID-19 and vaccination in patients with chronic liver diseases

The outbreak of coronavirus disease 2019(COVID-19)is a global pandemic.Many clinical trials have been performed to investigate potential treatments or vaccines for this disease to reduce the high morbidity and mortality.The drugs of higher interest include umifenovir,bromhexine,remdesivir,lopinavir/ritonavir,steroid,tocilizumab,interferon alpha or beta,ribavirin,fivapiravir,nitazoxanide,ivermectin,molnupiravir,hydroxychloroquine/chloroquine alone or in combination with azithromycin,and baricitinib.Gastrointestinal(GI)symptoms and liver dysfunction are frequently seen in patients with COVID-19,which can make it difficult to differentiate disease manifestations from treatment adverse effects.GI symptoms of COVID-19 include anorexia,dyspepsia,nausea,vomiting,diarrhea and abdominal pain.Liver injury can be a result of systemic inflammation or cytokine storm,or due to the adverse drug effects in patients who have been receiving different treatments.Regular monitoring of liver function should be performed.COVID-19 vaccines have been rapidly developed with different technologies including mRNA,viral vectors,inactivated viruses,recombinant DNA,protein subunits and live attenuated viruses.Patients with chronic liver disease or inflammatory bowel disease and liver transplant recipients are encouraged to receive vaccination as the benefits outweigh the risks.Vaccination against COVID-19 is also recommended to family members and healthcare professionals caring for these patients to reduce exposure to the severe acute respiratory syndrome coronavirus 2 virus.

Angiotensin-converting enzyme 2 receptors,chronic liver diseases,common medications,and clinical outcomes in coronavirus disease 2019 patients

The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the virus responsible for coronavirus disease 2019(COVID-19),enters affected cells through the angiotensin-converting enzyme 2(ACE2)receptor,which is highly expressed in type II alveolar cells,enterocytes,and cholangiocytes.SARS-CoV-2 infection causes fever,dry cough,and breathing difficulty,which can progress to respiratory distress due to interstitial pneumonia,and hepatobiliary injury due to COVID-19 is increasingly recognized.The hepatobiliary injury may be evident at presentation of the disease or develop during the disease progression.The development of more severe clinical outcomes in patients with chronic liver diseases(CLD)with or without cirrhosis infected with SARS-CoV-2 has not been elucidated.Moreover,there is limited data related to common medications that affect the disease severity of COVID-19 patients.Additionally,ACE2 receptor expression of hepatobiliary tissue related to the disease severity also have not been clarified.This review summarized the current situation regarding the clinical outcomes of COVID-19 patients with chronic liver diseases who were treated with common medications.Furthermore,the association between ACE2 receptor expression and disease severity in these patients is discussed.

Should people with chronic liver diseases be vaccinated against COVID-19?

Hepatic impairment in coronavirus disease 2019(COVID-19)may derive from cholangiocyte damage in the beginning,but not from direct infection of hepatocytes.Chronic liver disease patients co-infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)exhibited overexpression of angiotensin-converting enzyme 2 receptors and overwhelming cytokine storm.Consensus has been reached that we should encourage as many people as possible to be vaccinated in order to achieve herd immunity.SARS-CoV-2 vaccines can prevent or alleviate severe infection and cytokine storm.It is recommended that all adult patients with chronic liver diseases and liver transplant recipients should receive COVID-19 vaccines using the standard dose and schedule.Data is not yet sufficient to compare the efficacy of different types of vaccines used in chronic liver disease patients.

Definition and classification of acute-on-chronic liver diseases

Patients with chronic liver diseases(CLDs)develop acute liver injury and/or acute decompensation under the attack of various precipitants and present with significantly elevated alanine aminotransferase and/or total bilirubin levels,liver failure,or acute decompensation of liver cirrhosis,which is called acute-on-CLD(AoCLD).AoCLD accounts for the majority of patients hospitalized in the Department of Hepatology or Infectious Diseases.AoCLD is complicated by various clinical types,the severity of the disease,and may pose a high risk of death.To date,the definition of AoCLD is still vague,and a consensus concept of the clinical classification is lacking.This review aimed to define the concept and clinical types of AoCLD based on related studies and the literature.

Effects of SARS-CoV-2 infection on incidence and treatment strategies of hepatocellular carcinoma in people with chronic liver disease

BACKGROUND Chronic liver disease(CLD)was associated with adverse clinical outcomes among people with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.AIM To determine the effects of SARS-CoV-2 infection on the incidence and treatment strategy of hepatocellular carcinoma(HCC)among patients with CLD.METHODS A retrospective,territory-wide cohort of CLD patients was identified from an electronic health database in Hong Kong.Patients with confirmed SARS-CoV-2 infection[coronavirus disease 2019(COVID-19)+CLD]between January 1,2020 and October 25,2022 were identified and matched 1:1 by propensity-score with those without(COVID-19-CLD).Each patient was followed up until death,outcome event,or November 15,2022.Primary outcome was incidence of HCC.Secondary outcomes included all-cause mortality,adverse hepatic outcomes,and different treatment strategies to HCC(curative,non-curative treatment,and palliative care).Analyses were further stratified by acute(within 20 d)and post-acute(21 d or beyond)phases of SARS-CoV-2 infection.Incidence rate ratios(IRRs)were estimated by Poisson regression models.RESULTS Of 193589 CLD patients(>95%non-cirrhotic)in the cohort,55163 patients with COVID-19+CLD and 55163 patients with COVID-19-CLD were included after 1:1 propensity-score matching.Upon 249-d median follow-up,COVID-19+CLD was not associated with increased risk of incident HCC(IRR:1.19,95%CI:0.99-1.42,P=0.06),but higher risks of receiving palliative care for HCC(IRR:1.60,95%CI:1.46-1.75,P<0.001),compared to COVID-19-CLD.In both acute and post-acute phases of infection,COVID-19+CLD were associated with increased risks of allcause mortality(acute:IRR:7.06,95%CI:5.78-8.63,P<0.001;post-acute:IRR:1.24,95%CI:1.14-1.36,P<0.001)and adverse hepatic outcomes(acute:IRR:1.98,95%CI:1.79-2.18,P<0.001;post-acute:IRR:1.24,95%CI:1.13-1.35,P<0.001),compared to COVID-19-CLD.CONCLUSION Although CLD patients with SARS-CoV-2 infection were not associated with increased risk of HCC,they were more likely to receive palliative treatment than those without.The detrimental effects of SARS-CoV-2 infection persisted in post-acute phase.

Progress of mitochondrial and endoplasmic reticulum-associated signaling and its regulation of chronic liver disease by Chinese medicine

The endoplasmic reticulum(ER)is connected to mitochondria through mitochondria-associated ER membranes(MAMs).MAMs provide a framework for crosstalk between the ER and mitochondria,playing a crucial role in regulating cellular calcium balance,lipid metabolism,and cell death.Dysregulation of MAMs is involved in the development of chronic liver disease(CLD).In CLD,changes in MAMs structure and function occur due to factors such as cellular stress,inflammation,and oxidative stress,leading to abnormal interactions between mitochondria and the ER,resulting in liver cell injury,fibrosis,and impaired liver function.Traditional Chinese medicine has shown some research progress in regulating MAMs signaling and treating CLD.This paper reviews the literature on the association between mitochondria and the ER,as well as the intervention of traditional Chinese medicine in regulating CLD.

Inactivated SARS-CoV-2 booster vaccine enhanced immune responses in patients with chronic liver diseases

Chronic liver disease(CLD)entails elevated risk of COVID-19 severity and mortality.The effectiveness of the booster dose of inactivated SARS-CoV-2 vaccine in stimulating antibody response in CLD patients is unclear.Therefore,we conducted a cross-sectional study involving 237 adult CLD patients and 170 healthy controls(HC)to analyze neutralizing antibodies(NAbs)against SARS-CoV-2 prototype and BA.4/5 variant,anti-receptor binding domain(RBD)IgG,and total anti-SARS-CoV-2 antibodies.Serum levels of the total anti-SARS-CoV-2 antibodies,anti-RBD IgG and inhibition efficacy of NAbs were significantly elevated in CLD patients after the booster dose compared with the pre-booster dose,but were relatively lower than those of HCs.Induced humoral responses decreased over time after booster vaccination.The neutralization efficiency of the serum against BA.4/5 increased but remained below the inhibition threshold.All four SARS-CoV-2 antibodies,including total anti-SARS-CoV-2 antibodies,anti-RBD IgG and NAbs against prototype and BA.4/5,were lower in patients with severe CLD than those with non-severe CLD.After booster shot,age and time after the last vaccine were the risk factors for seropositivity of NAb against BA.4/5 in CLD patients.Additionally,white blood cell counts and hepatitis B core antibodies were the protective factors,and severe liver disease was the risk factor associated with seropositivity of total anti-SARS-CoV-2 antibodies.Overall,our data uncovered that antibody responses were improved in CLD patients and peaked at 120 days after the booster vaccines.All antibodies excepting total anti-SARS-CoV-2 antibodies declined after peak.CLD patients exhibited impaired immunologic responses to vaccination and weakened NAbs against BA.4/5,which hindered the protective effect of the booster shot against Omicron prevalence.Cellular immune responses should be further evaluated to determine the optimal vaccine regimen for CLD patients.

Efficacy of Vaccine Protection Against COVID-19 Virus Infection in Patients with Chronic Liver Diseases

The outbreak of coronavirus disease 2019 (COVID-19) has resulted in significant morbidity and mortality worldwide. Vaccination against coronavirus disease 2019 is a use-ful weapon to combat the virus. Patients with chronic liver diseases (CLDs), including compensated or decompensated liver cirrhosis and noncirrhotic diseases, have a decreased immunologic response to coronavirus disease 2019 vaccines. At the same time, they have increased mortality if infected. Current data show a reduction in mortality when patients with chronic liver diseases are vaccinated. A suboptimal vac-cine response has been observed in liver transplant recipi-ents, especially those receiving immunosuppressive therapy, so an early booster dose is recommended to achieve a better protective effect. Currently, there are no clinical data com-paring the protective efficacy of different vaccines in patients with chronic liver diseases. Patient preference, availability of the vaccine in the country or area, and adverse effect profiles are factors to consider when choosing a vaccine. There have been reports of immune-mediated hepatitis after coronavi-rus disease 2019 vaccination, and clinicians should be aware of that potential side effect. Most patients who developed hepatitis after vaccination responded well to treatment with prednisolone, but an alternative type of vaccine should be considered for subsequent booster doses. Further prospec-tive studies are required to investigate the duration of immu-nity and protection against different viral variants in patients with chronic liver diseases or liver transplant recipients, as well as the effect of heterologous vaccination.

Wnt/beta-catenin signaling and its modulators in nonalcoholic fatty liver diseases

Nonalcoholic fatty liver disease(NAFLD)is a global health concern associated with significant morbidity and mortality.NAFLD is a spectrum of diseases originating from simple steatosis,progressing through nonalcoholic steatohepatitis(NASH),fibrosis,and cirrhosis that may lead to hepatocellular carcinoma(HCC).The pathogenesis of NAFLD is mediated by the triglyceride accumulation followed by proinflam-matory cytokines expression leading to inflammation,oxidative stress,and mitochondrial dysfunction de-noted as“two-hit hypothesis”,advancing with a“third hit”of insufficient hepatocyte proliferation,lead-ing to the increase in hepatic progenitor cells contributing to fibrosis and HCC.Wnt/β-catenin signaling is responsible for normal liver development,regeneration,hepatic metabolic zonation,ammonia and drug detoxification,hepatobiliary development,etc.,maintaining the overall liver homeostasis.The key regula-tors of canonical Wnt signaling such as LRP6,Wnt1,Wnt3a,β-catenin,GSK-3β,and APC are abnormally regulated in NAFLD.Many experimental studies have shown the aberrated Wnt/β-catenin signaling dur-ing the NAFLD progression and NASH to hepatic fibrosis and HCC.Therefore,in this review,we have em-phasized the role of Wnt/β-catenin signaling and its modulators that can potentially aid in the inhibition of NAFLD.

Therapeutic Roles of Bile Acid Signaling in Chronic Liver Diseases

Bile acids(BAs)are the major metabolic product of cholesterol,having detergent-like activities and being responsible for absorption of lipid and lipid-soluble vitamins.Tn addition,it has been increasingly recognized that BAs are important signaling molecules,regulating energy metabolism and immunity.Under physiological circumstances,synthesis and transport of BAs are precisely regulated to maintain bile acid homeostasis.Disruption of bile acid homeostasis results in pathological cholestasis and metabolic liver diseases.During the last decades,BAs have been gradually recognized as an important therapeutic target for novel treatment in chronic liver diseases.This review will provide an update on the current understanding of synthesis,transport and regulation of BAs,with a focus on the therapeutic roles of bile acid signaling in chronic liver diseases.

Circulating copeptin level and the clinical prognosis of patients with chronic liver disease

BACKGROUND The relationship between copeptin and the severity of circulatory dysfunction and systemic stress response in patients with chronic liver disease(CLD)has been established.Nevertheless,the potential of serum copeptin levels to predict the prognosis of CLD patients remains unclear.AIM To conduct a systematic review and meta-analysis to investigate the correlation between serum copeptin and transplant-free survival(TFS)in this population.METHODS To achieve the objective of the meta-analysis,PubMed,Embase,the Cochrane Library,and the Web of Science were searched to identify observational studies with longitudinal follow-up.The Cochrane Q test was utilized to assess betweenstudy heterogeneity,and the I2 statistic was estimated.Random-effects models were employed to combine the outcomes,taking into account the potential influence of heterogeneity.RESULTS Ten datasets including 3133 patients were involved.The follow-up durations were 1 to 48 mo(mean:12.5 mo).Overall,it was shown that a high level of serum copeptin was associated with a poor TFS[risk ratio(RR):1.82,95%confidence interval:1.52-2.19,P<0.001;I2=0%].In addition,sensitivity analysis by omitting one dataset at a time showed consistent results(RR:1.73-2.00,P<0.05).Finally,subgroup analyses according to study country,study design,patient diagnosis,cutoff of copeptin,follow-up duration,and study quality score also showed similar results(P for subgroup difference all>0.05).CONCLUSION Patients with CLD who have high serum copeptin concentrations may be associated with a poor clinical prognosis.